3312 results

Soil Quality Evaluation Using the Soil Management Assessment Framework (SMAF) in Brazilian Oxisols with Contrasting Texture

Maurício Roberto Cherubin, Cássio Antônio Tormena, Douglas L. Karlen

29/Mar/2017

ABSTRACT The Soil Management Assessment Framework (SMAF) was developed in the U.S.A. and has been used as a tool for assessing and quantifying changes in soil quality/health (SQ) induced by land uses and agricultural practices in that region and elsewhere throughout the world. An initial study using SMAF in Brazil was recently published, but additional research for a variety of soils and management systems is still needed. Our objective was to use data from five studies in southern Brazil to […]

Release of Phosphorus Forms from Cover Crop Residues in Agroecological No-Till Onion Production

Rodolfo Assis de Oliveira, Jucinei José Comin, Tales Tiecher, Rogério Piccin, Luiza Michelon Somavilla, Arcângelo Loss, [...]

29/Mar/2017

ABSTRACT Cover crops grown alone or in association can take up different amounts of phosphorus (P) from the soil and accumulate it in different P-forms in plant tissue. Cover crop residues with a higher content of readily decomposed forms may release P more quickly for the next onion crop. The aim of this study was to evaluate the release of P forms from residues of single and mixed cover crops in agroecological no-till onion (Allium cepa L.) production. The experiment […]

Micromorphology of Paleosols of the Marília Formation and their Significance in the Paleoenvironmental Evolution of the Bauru Basin, Upper Cretaceous, Southeastern Brazil

Márcio Luiz da Silva, Alessandro Batezelli, Francisco Sérgio Bernardes Ladeira

29/Mar/2017

ABSTRACT Deduction of associated paleoenvironments and paleoclimate, definition of the chronosequence of paleosols, and paleogeographic reconstruction have become possible through the application of micromorphology in paleopedology. Micromorphology has also been useful in recognition of weathering processes and definition of minerals formed in succession. In this respect, the objective of this study was to identify the development of pedogenic processes and discuss their significance in the paleoclimate evolution of the Marília Formation (Maastrichtian) of Bauru Basin. Three sections of the Marília […]

Interaction between Thermotolerant Coliforms and Rhizobacteria in Soil Fertilized with Treated Domestic Wastewater

Paulo Fortes, Nara Lúcia Perondi Fortes, Eliana Maria de Araújo Mariano da Silva, Fabiana Brambatti

21/Mar/2017

ABSTRACT Studies on the survival of pathogenic microorganisms in the soil after use of wastewater for fertilization of agricultural crops report the effects of moisture, pH, organic matter, and soil temperature on microorganisms. There are few studies that assess the survival of these microorganisms in the rhizosphere of plants fertilized with wastewater. Thus, the aim of this study was to quantify the number of fecal coliforms and rhizobacteria (fluorescent Pseudomonas spp., Bacillus spp,) in the rhizosphere of winter and summer […]

Pedogenic Iron Oxides in Iron-Rich Oxisols Developed from Mafic Rocks

Danilo de Lima Camêlo, João Carlos Ker, Maurício Paulo Ferreira Fontes, Marcelo Metri Corrêa, Antonio Carlos Saraiva da Costa, Vander Freitas Melo

21/Mar/2017

ABSTRACT Despite the considerable amount of information on the mineralogical characteristics of pedogenic Fe oxides in Brazilian soils, there are few studies on Fe-rich soils developed from mafic rocks with taxonomic identities at lower categorical levels. This study evaluated the mineralogical characteristics of pedogenic Fe oxides in B horizons (Bw) of Fe-rich Oxisols developed from several mafic rocks in the state of Minas Gerais, Brazil. The Bw horizons were sampled at a 0.8-1.0 m depth in 13 Ferric and Perferric […]

Relationships between Agriculture, Riparian Vegetation, and Surface Water Quality in Watersheds

Tiago Broetto, Carlos Gustavo Tornquist, Ben-Hur Costa de Campos, Júlio Cézar Schneider

21/Mar/2017

ABSTRACT Agricultural land use and degradation of natural vegetation in riparian zones can impair water quality. This study was conducted in seven agricultural watersheds in Ibirubá, RS, Brazil, with the following objectives: identify relationships between concentrations of soluble phosphorus (Psol) and nitrate (NO−3) in surface water and agricultural use of soil and current vegetation in riparian zones, and assess the risk of eutrophication. Water samples from the main watercourses in each watershed were collected monthly from 10/2013 to 6/2014. Current […]

Characteristics of Soils in Highland Wetlands as a Subsidy to Identifying and Setting their Limits

Maria Tereza Warmling, Jackson Adriano Albuquerque, Jaime Antonio de Almeida, Maria Izabel Warmling

09/Mar/2017

ABSTRACT Palustrine areas and wetlands in particular are fragile ecosystems, with high biodiversity and high ecological productivity, and they provide benefits to society. The aim of this study was to describe and classify the main soils occurring in the wetlands of the Southern Plateau of Santa Catarina, and propose criteria for identification of hydromorphic environments as an aid in demarcation of their boundaries. Soils of four wetlands, in the municipalities of Bom Jardim da Serra, Bom Retiro, Lages, and Painel […]

The Use of DRIS for Nutritional Diagnosis in Oil Palm in the State of Pará

Gilson Sergio Bastos de Matos, Antonio Rodrigues Fernandes, Paulo Guilherme Salvador Wadt, Antônio José de Abreu Pina, Vinícius Ide Franzini, Helen Monique Nascimento Ramos

09/Mar/2017

ABSTRACT The oil palm crop has expanded significantly in the state of Pará, which has not been followed in a proportional manner by studies aiming at increasing yield through plant nutrition. The objective of this study was to evaluate general and specific norms of the Diagnosis and Recommendation Integrated System (DRIS) for genetic materials of oil palm (African and interspecific hybrid) at two ages (young and adult plants) and evaluate possible deficiencies in fertilization and soil correction practices. The DRIS […]

Nutrient Release, Plant Nutrition, and Potassium Leaching from Polymer-Coated Fertilizer

Henrique Bley, Clesio Gianello, Lenio da Silva Santos, Lisiane Priscila Roldão Selau

09/Mar/2017

ABSTRACT The increase in food consumption and limitations in food production areas requires improved fertilizer efficiency. Slow- or controlled-release fertilizers are an alternative for synchronizing nutrient availability with the plant demands, reducing losses to the environment. The aim of this study was to evaluate the efficacy of polymer-coated KCl compared with conventional KCl. The products were incubated in soil under controlled conditions to evaluate the time required for nutrient release. A greenhouse experiment was performed with corn plants in pots […]

Bulk Density Prediction for Histosols and Soil Horizons with High Organic Matter Content

Sidinei Julio Beutler, Marcos Gervasio Pereira, Wagner de Souza Tassinari, Michele Duarte de Menezes, Gustavo Souza Valladares, Lúcia Helena Cunha dos Anjos

09/Mar/2017

ABSTRACT Bulk density (Bd) can easily be predicted from other data using pedotransfer functions (PTF). The present study developed two PTFs (PTF1 and PTF2) for Bd prediction in Brazilian organic soils and horizons and compared their performance with nine previously published equations. Samples of 280 organic soil horizons used to develop PTFs and containing at least 80 g kg-1 total carbon content (TOC) were obtained from different regions of Brazil. The multiple linear stepwise regression technique was applied to validate […]

1 49 50 51 52 53 332